M4 vs. ZDP vs. XHP: Which one holds the fine edge longest?

singularity35 said:
M4 vs. ZDP vs. XHP: Which one holds the fine edge longest?
What's your experience? Thanks.
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If by "M4" you mean "CPM M4", then between ZDP-189 and and CPM M4, CPM M4 held an edge longer by a considerable margin for me when cutting manila rope. I have not tried XHP. And I don't know about "fine edge".

Forum > Knife Specific Discussion > Knife Reviews & Testing >
Comparison of CPM M4 HC, ZDP-189, M390, and S30V edge retention

http://www.bladeforums.com/forums/s...PM-M4-HC-ZDP-189-M390-and-S30V-edge-retention
 
knarfeng said:
If by "M4" you mean "CPM M4", then between ZDP-189 and and CPM M4, CPM M4 held an edge longer by a considerable margin for me when cutting manila rope. I have not tried XHP. And I don't know about "fine edge".

Forum > Knife Specific Discussion > Knife Reviews & Testing >
Comparison of CPM M4 HC, ZDP-189, M390, and S30V edge retention

http://www.bladeforums.com/forums/s...PM-M4-HC-ZDP-189-M390-and-S30V-edge-retention
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Yep, I mean CPM-M4 and by fine edge I mean that initial hair whittling edge.
 
In my uses, it seems that M4 will hold a fine edge (and overall) the longest. ZDP and XHP have both seemed close, with ZDP in the lead. These three knives were all Spydercos, for reference. All great steels, just different. :thumbup:

spydusse said:
I like how you didn't include your cts20cp para as you and I both know its leaps above these.
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Was just thinking the same thing. :D
 
spydusse said:
I like how you didn't include your cts20cp para as you and I both know its leaps above these.
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I don't know about that. I have to take pills every couple hours everyday due to an illness and have to cut them up. As soon as a knife starts to dull I can tell when cutting my pills as it gets quite a bit harder to cut and will start to crumble. I have used S90V, 20CP, and M4 so far and the M4 seems to hold a really sharp edge for quite a bit longer than either of the other 2. Like twice as long for that use and I'm cutting on a bamboo cutting board. I have just started using an M390 knife bit haven't used it enough to tell anything as I have been using the others for over a year. The M4 has really been impressing me lately.
 
Pills,never heard of that as a testing measurement before. Take a look at what cruicable has to say about wear resistance of cpm4 to s90v (wich is similar to 20cp http://www.crucible.com/PDFs/Knifemaker REV June 2010.pdf they show close to double the wear resistance of s90 over cpmm4
My bm lfti cpmm4 isn't close to my para 2 in cts20cp I mean leaps but that's probably the thick grind. I used a gayle bradley for three days and I saw wear ,not much but still more then I have with my para cts20cp in weeks of work at the same job.if its the bradley you are talking about I think you might be noticing less crumble effect because of the awesome hollow grind wich leaves almost no steel behind bevel as oppose to say a ffg of s90 or 20cp. As you start to get threw pill with a ffg past the bevel the grind of knife will push against top of pill you would see crumble from top not at bottom of cut.where as a hollow grind the only part of steel to hit pill would be the bevel and then air behind that, not to mention the bevel doesn't have to be as long on that grind to obtain a thirty degree angle as iit would on a ffg. So in turn your V is longer and wider at top.I could even see a sebenza with its awesome hollow grind of s30 excelling at this over s90 in ffg.now say you were to have 20cp reground so its ground from top to bottom like a true flat ground from top to edge like Ankerson did. (Awesome btw) you would see it excell over your hollow grind bradley
 
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My GB beats my Manix2 (cts-xhp) and my Stretch (zdp-189) in edge holding. Stuff cut varies from cardboard to hard plastic, paper, thin wire, rope and more.
I cannot comment on the pro's and cons of the various edge geometries.
Ironically, the GB also reaquires its edge the easiest on the Sharpmaker. So yes, CPM-M4 is an awesome steel in my (admittedly limited) experience.
 
Juste realized I never actually answered original post. Ide say m4,zdp then xhp. Zdp and xhp being very close
 
singularity35 said:
I understand but which one in your experience holds it longest Jim?
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It's gone as soon as you cut something..... And it doesn't take much cutting at all so I couldn't really say.

I am more interested in how long the steels hold a usable edge (working edge), been using my S90V Para 2 at work for 3 weeks and haven't had to touch the edge yet.
 
singularity35 said:
I understand but which one in your experience holds it longest?
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out of the three steels you listed, M4 IMO. also, because M4 is pretty tough, you could set the edge at a more acute angle and not have to worry about chipping (within reason).

which M4 knife are you looking at?
 
spydusse said:
Pills,never heard of that as a testing measurement before. Take a look at what cruicable has to say about wear resistance of cpm4 to s90v (wich is similar to 20cp http://www.crucible.com/PDFs/Knifemaker REV June 2010.pdf they show close to double the wear resistance of s90 over cpmm4
My bm lfti cpmm4 isn't close to my para 2 in cts20cp I mean leaps but that's probably the thick grind. I used a gayle bradley for three days and I saw wear ,not much but still more then I have with my para cts20cp in weeks of work at the same job.if its the bradley you are talking about I think you might be noticing less crumble effect because of the awesome hollow grind wich leaves almost no steel behind bevel as oppose to say a ffg of s90 or 20cp. As you start to get threw pill with a ffg past the bevel the grind of knife will push against top of pill you would see crumble from top not at bottom of cut.where as a hollow grind the only part of steel to hit pill would be the bevel and then air behind that, not to mention the bevel doesn't have to be as long on that grind to obtain a thirty degree angle as iit would on a ffg. So in turn your V is longer and wider at top.I could even see a sebenza with its awesome hollow grind of s30 excelling at this over s90 in ffg.now say you were to have 20cp reground so its ground from top to bottom like a true flat ground from top to edge like Ankerson did. (Awesome btw) you would see it excell over your hollow grind bradley
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I think people are talking about 2 different things. Overall edge holding and initial hair popping edge holding and I think the OP is interested in the latter. I wasn't saying that M4 would hold an edge longer than 20CP. I was saying that M4 will hold it's razor sharp edge longer than 20CP. This has been talked about quite a bit on here and that is S90V/ 20CP is a high vanadium content steel and it has lots of carbides in a steel matrix similar to rocks in concrete. When the steel is used some of the carbides can "chip" out on a very small scale which causes the steel to lose that razor sharp edge faster than some other steels yet it will keep its working edge for many times longer than most other steels.

When I cut my pills they cut easily with a razor sharp edge and once it starts to lose that edge it gets a little harder and causes the pill to crumble a little. The knife is not dull, its just not fresh off the stone sharp. I don't think geometry makes much of a difference because all knives cut equally well when they have just been sharpened. Even my Kershaw Volt in M390 which has a very thick blade and is a lot thicker than most of my knives behind the edge. When it is sharp it still goes through the pill almost effortlessly. When any of them lose the hair popping edge then it gets harder to cut my medicine. For this use, the M4 keeps the sharp edge quite a bit longer than the 20CP though neither are close to dull by most standards. You are also correct that I am talking about the Gayle Bradley. I also have used my M4 Rift and unfortunately it doesn't perform as well as the Spyderco. It does good but does not have as good of a heat treat and is probably a couple points softer. I think the first run of Gayle Bradleys tested at 64 HRC while most Benchmade M4 has tested at 60-61 HRC which is a pretty big difference. The Rift is my favorite knife and I would love for it to perform like the GB.

Hopefully my previous post is more clear now.
 
I can agree with m4 holding a fresh off the stone edge longer then 20cp as I felthoug holds that fresh of the stone edge longer then 20cp as well.that's said,my 20cp will still shave after 3weeks at the plant nursery were as zdp and xhp are done shaving after about a week give or take some days.I havnt been able to test spydercos m4 as extensively as those other steels because I hate the bradleys ergos and refuse to buy it(used the one I bought for my cousin for three busy days of work )it did hold up nice but on the third day I would say the keen edge was gone, still shaving though. So really we are talking about day 1 through 3 anything after that I give the edge to 20cp,no pun intended :)
 
jimnolimit said:
out of the three steels you listed, M4 IMO. also, because M4 is pretty tough, you could set the edge at a more acute angle and not have to worry about chipping (within reason).

which M4 knife are you looking at?
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Spyderco Gayle Bradley's CPM-M4.
 
CPM-M4 for sure with a Spyderco heat treat. Aren't carbon steels known for holding a fine edge? I would just assume that's the case because of a lack of Chromium carbides, which are bigger than vanadium carbides. It also seems like a lot of the very high end(and costly) Japanese kitchen knives are in some super hard carbon steel. Though in M390's case, it seems to hold a fine edge just as well as M4, probably because of the 3rd generation PM process. In any case, it seems like a fine grain structure is crucial. Toughness will help depending on what you're cutting, but in the kitchen it doesn't seem like toughness factors into it given all the super hard Rc 65+ knives from Japan.
 
I bought a GB in cpm m4, and it stays sharper longer than any steel I have ever owned. It sharpens easier than vg10 for me aslo.

I usually pair it with my salt1 for wet stuff/ money clip
 
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